Unmanned Aerial Vehicles (UAVs) generally include any aircraft capable of controlled flight without a human pilot onboard. UAVs may be controlled autonomously by onboard computer processors and/or by a remotely located human pilot. Like pilot-driven helicopters, some UAVs can be configured as rotor-based aircraft. For example, several manufacturers offer commercially available UAVs that include four rotors, otherwise known as “quadcopters.” Often UAVs are fitted with image capture devices such as cameras that can be configured both to record images (and video) of the surrounding environment and increasingly to facilitate autonomous visual navigation by the UAV.